Yongwoon Kim
Full-stack Engineer + AI/LLM Specialist
I turn complex business problems into production-grade full-stack and AI systems.
15+ years shipping production-grade full-stack and AI systems across 11 companies — from LegalTech and HR platforms to real-time streaming, e-commerce, and embedded software. Currently leading architecture and delivery for RAG-powered products with OpenAI, LangChain, Next.js, Go, and Python, deployed on AWS · GCP · Azure.
Tech Stack
Featured Projects
A closer look at the work I'm most proud of — from idea to production.
LIMA — Legal Intelligence Modular Architecture
Tech Lead / Backend Architect
Led the architecture and implementation of LegalOn's next-gen legal AI platform on GCP. Designed FastAPI + Golang microservices over gRPC, owned K8s rollout, and hardened LLM inference pipelines for contract review at enterprise scale.
Shipped the foundation powering LegalOn's flagship AI contract review across thousands of enterprise users.
Luum Job Platform
Tech Lead / Full-Stack
Drove end-to-end delivery of a modern job-matching platform — Next.js + TypeScript frontend, NestJS + GraphQL backend, multi-cloud infra on AWS + Kubernetes. Set up CI/CD, observability, and the engineering playbook from day one.
Took the product from zero to production, scaling the team and codebase alongside the launch.
Upload Detection System
Backend Engineer
Designed and built a real-time file upload detection service in Golang + Echo, backed by PostgreSQL and deployed to GKE via Terraform. Emphasis on throughput, observability, and safe zero-downtime rollouts.
Core reliability building block for BizLink's document automation product.
Career History
BizLink, Inc.
2025.06 ~ 2026.03LegalOn Technologies, Inc.
2020.02 ~Luum, Inc.
2023.09 ~ 2025.01Drecom Co.,Ltd.
2019.09 ~ 2020.01Emerada Co., Ltd.
2019.03 ~ 2019.08Every, Inc.
2018.10 ~ 2019.02GREE, Inc.
2017.09 ~ 2018.09DWANGO Co., Ltd.
2016.01 ~ 2017.09Zappallas,Inc.
2013.12 ~ 2015.12ANDAMUL, INC.
2011.05 ~ 2013.12DigitalCraft, Inc.
2010.07 ~ 2011.05BizLink, Inc.
2025.06 ~ 2026.03
SES engineer handling contract development for multiple companies. RPA system design/development and GCP infrastructure construction (Terraform). Illegal upload detection system backend design and GCP multi-cloud infrastructure construction (Terraform, Kubernetes). Distributed system development using Python + Flask, Go + Echo, Protocol Buffers, gRPC.
LegalOn Technologies, Inc.
2020.02 ~
Developed AI/NLP annotation platforms and contract management systems. Frontend: Vue.js, Nuxt.js, React, Next.js, TypeScript, Tailwind CSS. Backend: Golang + Gin framework, Ruby + Ruby on Rails, Hanami framework. Infrastructure: Kubernetes, Docker, AWS, GCP, Azure multi-cloud. Led 22+ enterprise projects from architecture design to deployment.
Luum, Inc.
2023.09 ~ 2025.01
Developed AI-powered resume generation platform. Frontend: React. Backend: Golang + Gin framework, Ruby + Ruby on Rails. AI/ML: OpenAI GPT, LangChain RAG systems. Infrastructure: AWS, Kubernetes, Docker. Comprehensive HR platform that automatically generates career documents from LinkedIn profiles and matches with job listings. Designed and implemented LangChain-based AI pipeline.
Drecom Co.,Ltd.
2019.09 ~ 2020.01
Developed community and promotion platforms for user acquisition and retention in gaming and web services. Frontend: React. Backend: Ruby + Ruby on Rails. Database: MongoDB. Infrastructure: AWS. Built real-time user interaction systems and serverless functions.
Emerada Co., Ltd.
2019.03 ~ 2019.08
Developed B2B cash flow management and financial analysis platform. Frontend: React, TypeScript. Backend: Ruby + Ruby on Rails. Database: PostgreSQL. Infrastructure: AWS. Implemented real-time dashboards and financial analysis tools.
Every, Inc.
2018.10 ~ 2019.02
Developed video-based e-commerce platform. Backend: Golang + Echo framework. Provided innovative shopping experience integrating real-time streaming with product sales. Built high-performance backend API and real-time data processing systems.
GREE, Inc.
2017.09 ~ 2018.09
Developed lifestyle platform providing restaurant, travel, hotel, and tourism information. Backend: Ruby + Ruby on Rails, PHP + Laravel. Database: MySQL. Infrastructure: AWS. Built high-traffic handling system and designed scalable architecture. Developed user review and recommendation systems.
DWANGO Co., Ltd.
2016.01 ~ 2017.09
Developed animation and music streaming platforms 'dwango.jp' and 'animelo mix'. Frontend: Backbone.js SPA. Backend: Ruby + Padrino, Java + Spring. Database: MySQL, Oracle. Infrastructure: AWS. Built large-scale content management and streaming platform systems.
Zappallas,Inc.
2013.12 ~ 2015.12
Developed smartphone games targeting female audiences. Built social game platform with JavaScript + PHP + MySQL. Implemented user interaction and social features.
ANDAMUL, INC.
2011.05 ~ 2013.12
Developed novel games for major platforms including Gree, Mobage, MIXI, and Hangame. Frontend: JavaScript, jQuery, CSS. Backend: PHP. Database: MySQL. Game engine development and multi-platform API integration.
DigitalCraft, Inc.
2010.07 ~ 2011.05
Developed embedded systems and STM32 microcontroller modules based on TOPPERS RTOS. Development Environment: Linux, Cygwin. Language: C++. Implemented real-time OS and hardware control software. Designed and optimized TECS component architecture.
Let's build something together
Looking for help on a specific engineering challenge? I take on consulting, contract, and full-time engagements. Here are a few ways I can help:
System architecture & API design for full-stack and AI products
Production-grade AI/LLM systems — RAG pipelines, agent workflows, and integrations
Tech leadership & end-to-end delivery across backend, frontend, and infra
Multi-cloud engineering on AWS, GCP, and Azure (Kubernetes, Terraform)
Drop me a message below, and I'll get back to you within 2 business days.